SCR Rain or Leak Alarm (CB22097E)

This sensitive circuit was found in old documentation. The SCR can be any of the 106 series and the transistor a BC548.

Telemetry demodulator (CB9693E)
Found in old American documentation, this circuit demodulates signals from 1 kHz to 10 kHz for...
Resistor Test (CB17501E)
This simple circuit is a continuity test that, in addition to testing resistors, can also test...
Emergency Pulser (CB4548E)
This circuit was obtained from an English magazine from 1985. It consists of a pulser that drives...